I dunno yet, I only played the first 1 1/2 levels this morning. It was a blast though. I forgot so many of Duke's quotes and hearing them again was awesome.
"Your face, your ass, what's the difference?" and "I don't have time to play with myself." were especially welcome.
The only issue I can see people having is the autoaim function. You kind of need it to deal with the many flying enemies. It feels closer to the PC original if you leave it on but I know tons of people hate using autoaim anything.